The present invention relates to a device for holding preferably disk-shaped plastic substrates, such as CDs, DVDs and recording media of this type, so that they can be picked up and deposited, having a holding device on which at least one support unit for the plastic substrate is held, and a pickup and/or deposit device, from which the plastic substrate can be picked up, or respectively on which it can be deposited.
With such a device employed in the course of processing disk-shaped plastic substrates, the support unit has a plate-shaped mask, from whose underside a pin projects, on whose circumference at least one pair of resiliently seated locking spheres are arranged opposite each other. The distance of these spheres from the underside of the mask is equal to or greater than the thickness of the plastic substrates to be processed. With this known device the pin of the support unit is inserted into the centered hole of the plastic substrate, so that the plastic substrate can snap behind the resiliently seated spheres. During transport of the plastic substrate from a pickup station to a transfer station, the plate-shaped mask holding the plastic substrate is held, with the plastic substrate downwardly suspended, with the aid of an electromagnet arranged on a transport arm which is pivotable in the horizontal plane. At the transfer station to a processing device, the plastic substrate provided with the plate-shaped mask is taken over by a vacuum holding device after the electromagnet is switched off. The removal of the plastic substrate from the plate-shaped mask, which in turn is held by an electromagnet, takes place by pulling it off by means of the vacuum. Since this known device requires electromagnets at the support arm and resiliently seated locking spheres at the plate-shaped mask, this device is relatively elaborate in design and therefore only suited for those transport devices which, like the above mentioned pivot arm, only offer two transport spaces.
It is an object of the present invention to provide a device for holding preferably disk-shaped plastic substrates of the type mentioned at the outset, which can be picked up and deposited, is designed in a simpler way and is suitable in particular for those transport devices, which are equipped with several transport spaces and move the plastic substrates in a plane which is different from the horizontal plane.
This object is attained by provision of a device for holding preferably disk-shaped plastic substrates of the type mentioned at the outset, which can be picked up and deposited. The device having a support unit with a disk-shaped base body which has on its side facing a holding device a cylindrical protrusion on which a disk-shaped plastic substrate can be placed and which can be plugged into or releasably held mechanically or in a permanent-magnetic way in a recess of the holding device.
By means of the steps in accordance with the present invention it is achieved that the disk-shaped plastic substrates can be held in a considerably simpler way and independently of the spatial position of the holding device. In this way holding of the plastic substrates, together with holding of the support unit on the holding device, is achieved without any further steps. It is assured here that when the plastic substrate is received by the support unit, the plastic substrate is unstressed and therefore not placed under a load. The steps in accordance with the present invention are advantageous in particular in connection with transport devices used for cooling the plastic substrates, which had previously been produced by means of an injection molding process. In this case a plurality of transport spaces are provided, which have been designed in a simple manner as pluggable and releasable held pickups, wherein it is not necessary to supply these transport spaces, which are equipped with a holding device, with either electrical energy or with a vacuum or the like. This makes the holding of the plastic substrates structurally particularly simple. Moreover, it is assured that the plastic substrate itself remains unstressed and is therefore not placed under a load, not only when being picked up by the holding device, but also when the plastic substrate is being pulled off the holding device, or respectively is deposited on the deposit device.
The pluggable and releasable holding of the support unit at the holding device can be provided by mechanical locking means, for example. However, in a preferred embodiment of the present invention, the support unit can be pulled out of the holding device by means of a vacuum device arranged in the pickup and/or deposit device. This arrangement provides for permanent-magnetic holding. In this case, an advantageous structural design results from the characteristics whereby a permanent-magnetic disk is arranged in the recess of the holding device, and the support unit is at least partially made of a magnetic metal, with the support unit having an axial through-bore which receives a metal bolt.
By means of the characteristic whereby the disk-shaped base body of the support unit is provided with a second cylinder protrusion which enters with play into the depression of the pickup and/or deposit device ina centering manner it is achieved that the vacuum required for pulling the plastic substrate off the holding device can be applied to the underside of the base body of the support unit without any further connecting bores. By means of this step it is also achieved that no direct stress is applied to the plastic substrate when removing it from the holding device, because the plastic substrate is not held by the vacuum, but by the support unit, and is separated from the holding device.
With the disk-shaped base body of the support unit inserted into a depression of the pickup and/or deposit device flush with the surface are provided, the plastic substrate does not only rest on the base body of the support unit, but also directly on the pickup and/or deposit device.
With the pickup and/or deposit device moved toward the holding device, the pickup and/or deposit device is moved toward the holding device for picking up, or respectively depositing the plastic substrate. In this connection it is practical to provide the pickup and/or deposit device with a support for receiving the disk-shaped base body and the disk-shaped plastic substrate, and a pressure plate which is connected with a lift drive, the pressure plate being kept at a distance from the support by a compression spring in order to limit a force possibly acting on the holding device to a minimum.
The characteristies of a holding device constituted by a rotating unit provided with several radial arms and a horizontally rotating shaft, and a support unit received on each arm are provided for the use of the device, in particular in connection with one for cooling disk-shaped plastic substrates directly after they have been injection molded, so that the plastic substrates can be cooled in the course of a complete revolution of the rotating unit in the exemplary embodiment. Moreover, an arrangement which saves space in the horizontal plane results from this, which furthermore results in improved cooling, while preventing a heat accumulation. It is practical here in accordance with the characteristic whereby a pickup station and a deposit station, which preferably follows after a full revolution in the direction of rotation are assigned to the rotating unit to provide the pickup and the deposit devices at two separate stations.
Further details of the present invention can be found in the subsequent description, in which the invention will be described in greater detail and explained by means of the exemplary embodiment represented in the drawings.